Does reporting a small accident automatically raise your insurance premium?

A stupid guy bumped into my bros car and we're trying to decide to involve the insurance, but my dad says the insurance will go up. We already got repair quotes for my bros car, and now the guy is not picking up his phone, as we agreed when he hit the car that he'd pay cash.

Not true. Your rate CAN go up if you are not at fault. I was rear-ended last summer causing $800 damage to the back of my car. The cop determined it was her fault. She was difficult to deal with so I felt I had to notify my insurance company, but her insurance co. ended paying for everything including a rental and being VERY nice to me in case I pulled some "hurt neck" crap. My rate went up almost 20%! I have NEVER been in an accident before, and certainly not one in which I was at fault. I'm pretty angry but I'm in one of the most expensive states for insurance so I'll probably just ride it out.